Detecting and managing information on various articles by using an RFID tag mounted on an article have become widely used techniques. As the RFID tag, an RFID tag that includes an antenna conductor for performing transmission and reception of information by using a radio wave in an ultra-high frequency (UHF) band or the like and a semiconductor element such as an integrated circuit (IC) or the like is in wide use now.
Information is transmitted and received between the antenna conductor of the RFID tag and an external device such as a reader/writer having a function of transmitting and receiving a radio wave. A signal that is transmitted and received is, for example, stored or retrieved in the semiconductor element. The semiconductor element also functions as a power supply unit for the antenna conductor (for example, refer to PTL 1).